Re: 2.6.22-rc2 built on ppc

Segher Boessenkool wrote:

quoted

quoted

I don't know what's to blame for the warnings --- new gcc versions or
the change from do { } while (0) to ((void)0)?  Either way, the compiler
should comprehend that the arguments stuffed into the dma_unmap_single
macro are _not_ unused by accident; it should stay quiet and optimize
the unused variables away if run with -Osomething.

There is not much that the compiler can do by itself, since the macro
expansion happens in the preprocessor.

Even if the compiler could see that the variables are
used as macro arguments, this doesn't automatically
equate to it being able to infer the variables are
unused on purpose.

Strange.  I believe we had code before with variables that were only
used in macros that expanded to <nil>, notably debug logging macros
which were usually configured out.  Perhaps I'm mistaken.
-- 
Stefan Richter
-=====-=-=== -=-= =-=--
http://arcgraph.de/sr/